CN115036665A - Device and method for terahertz vibration absorption spectroscopy on silicon waveguide enhancement chip - Google Patents
Device and method for terahertz vibration absorption spectroscopy on silicon waveguide enhancement chip Download PDFInfo
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 36
- 239000010703 silicon Substances 0.000 title claims abstract description 36
- 238000004847 absorption spectroscopy Methods 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 title abstract description 11
- UMIVXZPTRXBADB-UHFFFAOYSA-N benzocyclobutene Chemical compound C1=CC=C2CCC2=C1 UMIVXZPTRXBADB-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000010453 quartz Substances 0.000 claims abstract description 20
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 10
- 230000003993 interaction Effects 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 28
- GUBGYTABKSRVRQ-XLOQQCSPSA-N Alpha-Lactose Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@@H](CO)O[C@H](O)[C@H](O)[C@H]1O GUBGYTABKSRVRQ-XLOQQCSPSA-N 0.000 claims description 22
- 229930195727 α-lactose Natural products 0.000 claims description 20
- 238000010521 absorption reaction Methods 0.000 claims description 16
- 239000010410 layer Substances 0.000 claims description 16
- 230000000694 effects Effects 0.000 claims description 10
- 238000002198 surface plasmon resonance spectroscopy Methods 0.000 claims description 5
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- GUBGYTABKSRVRQ-QKKXKWKRSA-N Lactose Natural products OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O GUBGYTABKSRVRQ-QKKXKWKRSA-N 0.000 description 2
- 239000012472 biological sample Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- CFBGXYDUODCMNS-UHFFFAOYSA-N cyclobutene Chemical compound C1CC=C1 CFBGXYDUODCMNS-UHFFFAOYSA-N 0.000 description 2
- 239000008101 lactose Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229920001909 styrene-acrylic polymer Polymers 0.000 description 2
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P3/00—Waveguides; Transmission lines of the waveguide type
- H01P3/12—Hollow waveguides
- H01P3/121—Hollow waveguides integrated in a substrate
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3581—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation
- G01N21/3586—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation by Terahertz time domain spectroscopy [THz-TDS]
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P3/00—Waveguides; Transmission lines of the waveguide type
- H01P3/12—Hollow waveguides
- H01P3/123—Hollow waveguides with a complex or stepped cross-section, e.g. ridged or grooved waveguides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P3/00—Waveguides; Transmission lines of the waveguide type
- H01P3/12—Hollow waveguides
- H01P3/14—Hollow waveguides flexible
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Abstract
The invention discloses a device and a method for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement chip. The device comprises a silicon waveguide, a benzocyclobutene dielectric layer and a quartz substrate from top to bottom in sequence, wherein the silicon waveguide is provided with a terahertz incident channel, a terahertz emergent channel and a sample bearing area which penetrate through the surface of the benzocyclobutene dielectric layer; the terahertz incident channel and the terahertz emergent channel are respectively connected to two sides of the sample bearing area; the biconical long waveguide is paved on the surface of the benzocyclobutene dielectric layer along the terahertz incident channel, the sample bearing area and the terahertz emergent channel. According to the terahertz absorption spectrum intensity enhancement method, the channel waveguide, the middle sample bearing area and the conical long waveguide are used for enhancing the surrounding local optical field, when an analyte is located in the channel and the sample bearing area, the enhanced optical field fully interacts with an object to be measured, the terahertz absorption spectrum intensity can be remarkably improved, and the method has applicability to terahertz absorption spectrum.
Description
Technical Field
The invention belongs to the field of terahertz wave devices, and particularly relates to a device and a method for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement chip.
Background
Terahertz (THz) absorption spectroscopy is a powerful analytical chemistry tool that can detect intermolecular vibrations of chemical and organic molecules. The study of these intermolecular vibrations is useful to reveal the kinetic characteristics of large biomolecules. Free space absorption spectroscopy is a common conventional method of terahertz spectroscopy and has been widely used to study material properties. Due to the diffraction limit and the long wavelength of the terahertz wave, a large amount of sample material is required in the measurement process. In addition, the length of the interaction between the terahertz wave and the sample under test is limited by the available amount of sample material. Finally, due to the low power of the terahertz source and the water vapor absorption effect in free space, such devices have a low signal-to-noise ratio and are not capable of capturing weak absorption features. It is worth noting that while the signal-to-noise ratio can be further improved by optimizing the apparatus in free space, enclosing the part of the apparatus and using a dry gas to purge the medium, such methods increase the cost of detection and increase the volume of the apparatus. In some recent studies, the sensitivity of free-space devices has been improved by using local electric fields in super-surface structures. Terahertz waveguides have wide applications in sensing and spectroscopy applications. Waveguide-based terahertz spectroscopy allows terahertz signals to interact with a sample in a waveguide, which has many advantages over free space devices. First, fewer samples are required. In waveguide-based devices, the waveguide modal field distribution (with subwavelength characteristics) interacts with the sample, and thus, the subwavelength sample can interact with the entire modal power. Secondly, a better signal-to-noise ratio can be obtained as the wave propagates within the waveguide. Patent 1[ CN202010839539.1] discloses a slit optical waveguide sensor based on surface-enhanced infrared absorption spectrum, which utilizes a slit waveguide structure to limit light in a slit with a low refractive index, a local optical field around the slit is enhanced by a slit of a metal antenna in the slit, and when an analyte fills the slit, the enhanced optical field fully interacts with an object to be measured, thereby improving the sensitivity of the sensor. Due to the structural design and the limitation of materials, the method can work in an infrared band and cannot work in a terahertz band. In the terahertz frequency range, there are several metal waveguides used for waveguide-based absorption spectroscopy: single wire waveguides, microstrip lines and coplanar waveguides and parallel plate metal waveguides. While these metallic waveguides reduce the amount of sample material required, their performance degrades rapidly with increasing operating frequencies due to the inherent loss of metallic waveguides in the terahertz frequency range. Meanwhile, the conventional waveguide enhancement structure has a limited enhancement factor and cannot enhance the absorption spectrum to a larger extent.
Disclosure of Invention
The invention aims to solve the problems that terahertz waves of the existing structures such as rectangular waveguide, ridge waveguide and metal waveguide are limited in a dielectric layer and cannot interact with an object to be detected, and the sensitivity of terahertz absorption spectrum is low due to the inherent loss of the metal waveguide, and provides a device and a method for terahertz vibration absorption spectrum on a silicon waveguide enhancement chip. According to the terahertz absorption spectrum detection method, the local optical field around is enhanced by utilizing the channel waveguide, the middle sample bearing area and the conical long waveguide, when an analyte is positioned in the channel and the sample bearing area, the enhanced optical field fully interacts with the object to be detected, the terahertz absorption spectrum intensity can be obviously improved, and the method has applicability to terahertz absorption spectrum.
The invention adopts the following specific technical scheme:
the invention provides a device for terahertz vibration absorption spectroscopy on a silicon waveguide reinforcing sheet, which is formed by stacking different functional layers, wherein the device comprises a silicon waveguide, a benzocyclobutene dielectric layer and a quartz substrate in sequence from top to bottom, and the silicon waveguide is provided with a terahertz incident channel, a terahertz emergent channel and a sample bearing region, wherein the terahertz incident channel, the terahertz emergent channel and the sample bearing region penetrate through the surface of the benzocyclobutene dielectric layer; the terahertz incident channel and the terahertz emergent channel are respectively connected to two sides of the sample bearing area; the double-conical long waveguide is laid on the surface of the benzocyclobutene dielectric layer along the terahertz incident channel, the sample bearing area and the terahertz emergent channel, one end of the double-conical long waveguide, which is positioned on the terahertz incident channel side, is used as an input end, and the other end of the double-conical long waveguide, which is positioned on the terahertz emergent channel side, is used as an output end; terahertz waves are input from the input end, evanescent waves can be generated on the surface of the waveguide, interaction between the terahertz waves in the sample bearing area and a sample to be detected is enhanced, and terahertz wave signals after the interaction are output from the output end.
Preferably, the double-cone long waveguide is a double-cone long straight waveguide and is laid along the terahertz incident channel, the sample bearing area and the terahertz emergent channel in a straight line.
Preferably, the biconical long waveguide is a curved waveguide, and a waveguide section located in the sample bearing region is curved in a wavy line manner.
Preferably, the quartz substrate is made of quartz, and has a relative dielectric constant of 4.45;
preferably, the styrene-acrylic cyclobutene dielectric layer is made of styrene-acrylic cyclobutene and has a relative dielectric constant of 2.45.
Preferably, the waveguide material of the silicon waveguide and the biconical long waveguide is high-resistance silicon, the relative dielectric constant is 11.69, the resistivity is 5k omega cm, and the thickness is 80-120 mu m.
Preferably, the terahertz incident channel and the terahertz emergent channel are both rectangular, the width is 570-590 um, and the length is 4-5 mm; the sample bearing area is rectangular, the length of the sample bearing area is 6-8 mm, and the width of the sample bearing area is 3-6 mm.
Preferably, the width of the biconical long straight waveguide is 170-190 um, and the thickness of the biconical long straight waveguide is 80-120 um.
Preferably, the bending radius of the bent waveguide is 0.9-1.1 mm.
In a second aspect, the invention provides a polycrystalline alpha-lactose terahertz absorption spectrometry method using the device according to any one of the first aspect, which comprises the following steps: firstly, adding polycrystalline alpha-lactose to be detected into a sample bearing area, and fully contacting with the biconical long waveguide; then, terahertz waves are focused by a lens and input into the biconical long waveguide through the input end of the biconical long waveguide, corresponding evanescent waves are formed on the surface of the waveguide, an electromagnetic enhancement effect is generated near the waveguide so as to enhance the interaction between the incident terahertz waves and the alpha-lactose material in the sample bearing area, the absorption of the alpha-lactose material on the incident waves is enhanced near the surface plasmon resonance frequency point, and the terahertz reflected signals after the interaction are emitted from the output end of the biconical long waveguide and then detected.
Compared with the prior art, the invention has the following beneficial effects:
the terahertz absorption spectrum enhancement device structure provided by the invention adopts a waveguide structure of a silicon-benzocyclobutene-quartz structure, a long waveguide penetrates through a sample bearing area to be fully contacted with a sample, an incident terahertz wave is injected into the waveguide to generate an evanescent wave on the surface of the waveguide, the evanescent wave and the sample in the sample bearing area are fully acted, and the electromagnetic enhancement effect is utilized to realize the enhanced terahertz absorption spectrum detection of a trace sample. In addition, by using an advanced manufacturing process of a silicon-based device, a waveguide structure of a silicon-benzocyclobutene-quartz structure can be changed, thereby further enhancing the intensity of capturing a fingerprint. The absorption spectrum enhancement device has a novel structure, the test method is convenient and fast to operate, and a local enhanced terahertz electric field can be obtained by using evanescent waves, so that the enhanced terahertz absorption spectrum measurement of biological samples (including solution samples) is realized.
Drawings
FIG. 1 is a schematic diagram of an absorption spectrum enhancement structure of a long straight waveguide according to the present invention;
FIG. 2 is a schematic view of a curved waveguide absorption spectrum enhancement structure of the present invention;
FIG. 3 is a graph showing the comparison of the absorption spectra of two waveguide structures according to the present invention.
In the figure: 1 is a quartz substrate; 2 is a benzocyclobutene dielectric layer; 3 is a silicon waveguide; 4 is a biconical long straight waveguide; 5 is a terahertz incident channel; 6 terahertz wave exit channel; 7 is a sample bearing zone; and 8 is a curved waveguide.
Detailed Description
The invention will be further elucidated and described with reference to the drawings and the detailed description. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.
As shown in fig. 1 and fig. 2, in a preferred embodiment of the present invention, two different devices for enhancing terahertz vibration absorption spectrum on a silicon waveguide chip are provided, the devices are formed by stacking different functional layers, that is, a silicon waveguide 3, a benzocyclobutene dielectric layer 2 and a quartz substrate 1, from top to bottom, the two devices have different biconical long waveguides, and the rest of the structures are the same. The silicon waveguide 3 is provided with a terahertz incident channel 5, a terahertz emergent channel 6 and a sample bearing area 7 which penetrate through the surface of the benzocyclobutene dielectric layer 2. The sample bearing area 7 is located in the center of the silicon waveguide 3 and used for bearing a sample to be tested, and the terahertz incident channel 5 and the terahertz emergent channel 6 are respectively connected to two sides of the sample bearing area 7. The biconical long waveguide is paved on the surface of the benzocyclobutene dielectric layer 2 along the terahertz incident channel 5, the sample bearing area 7 and the terahertz emergent channel 6, wherein one end of the biconical long waveguide, which is positioned at the terahertz incident channel 5 side, is used as an input end, and one end of the biconical long waveguide, which is positioned at the terahertz emergent channel 6 side, is used as an output end. The biconical long waveguide is a waveguide with two tapered ends. In the device, terahertz waves are input from an input end, evanescent waves can be generated on the surface of the waveguide, the interaction between the terahertz waves in the sample bearing area 7 and a sample to be detected is enhanced, and terahertz wave signals after the interaction are output from an output end.
Two different forms of the biconical elongated waveguide differ in whether they are curved or not. The first biconical long waveguide shown in fig. 1 is a biconical long straight waveguide 4, which is laid along a terahertz incident channel 5, a sample bearing region 7, and a terahertz emergent channel 6. The second biconical elongate waveguide shown in fig. 2 is a curved waveguide 8, the waveguide section located in the sample-supporting region 7 being curved in the form of a wavy line. The two kinds of double-tapered long waveguides are different in arrangement form, but the working principle is similar, terahertz waves are input from the input end of the tapered long waveguide, an evanescent field of a waveguide fundamental mode extends out of a waveguide fiber core area and interacts with a material sample around the waveguide, the terahertz waves after the interaction are output in a short time, and output detection signals are used for subsequent signal detection and processing.
The invention also provides a test method based on the terahertz absorption spectrum enhancement, a sample to be tested is filled in a sample bearing area, a terahertz source is utilized to inject terahertz waves into the biconical long waveguide, the incident terahertz waves enter the sample bearing area along the biconical long waveguide, evanescent waves are generated near the biconical long waveguide, as a part of mode fields are limited in the waveguide, only the part of fields outside the biconical long waveguide generate interaction through the sample, and the terahertz waves after the interaction are output from the output end of the biconical long waveguide for subsequent signal detection and processing.
When the sample-bearing zone is filled with a lossy sample, the output power can be expressed as
Wherein, P 0 Represents the input power of the terahertz wave, P represents the output power, alpha WG Representing the loss of the waveguide, alpha S Indicating sparse absorption of the lossy material, L indicating the length of the waveguide and the lossy material, and Γ indicating the interaction factor of the waveguide mode and the lossy material interacting. The incident terahertz waves form a plasmon resonance effect on the biconical long waveguide, an electric field enhancement effect is further generated, the interaction between the incident waves and the filled sample is enhanced, the absorption of the sample on the incident waves is enhanced near a resonance frequency point, and the acted terahertz waves are emitted from the output long waveguide to be detected.
Furthermore, the multiplier of the absorption coefficient of the loss material around the long waveguide is increased, so that the sensitivity to the loss of the tested material can be improved. The interaction factor (Γ) is a function of the waveguide geometry, formulated as
Wherein v is S Is the speed, v, of the electromagnetic wave in the sample material medium en Is the energy velocity of the waveguide and f is the fill factor. Therefore, the interaction factor can be enhanced by modifying the cross section of the silicon-benzocyclobutene-quartz structure waveguide. For example, tapering the channel waveguide to a narrower width results in an increase in the evanescent portion of the mode in the cladding region. Further, by creating a groove region in the middle of the channel waveguide, the terahertz wave can be confined in the groove region to produce a stronger interaction with the sample material. In addition, the interaction between the terahertz wave and the sample material can also be enhanced by increasing the length of the interaction, as shown in fig. 2, the waveguide is made into a curved waveguide structure of a silicon-benzocyclobutene-quartz structure, and the curved long waveguide structure curved in a wavy line form can increase the interaction length between the terahertz wave and the sample material, so that the terahertz absorption spectrum intensity can be further improved.
In both types of devices, the materials and parameters of the components can be as follows:
the quartz substrate 1 is made of quartz and has a relative dielectric constant of 4.45; the benzocyclobutene dielectric layer 2 is made of benzocyclobutene and has a relative dielectric constant of 2.45. The silicon waveguide 3 and the biconical long waveguide are made of high-resistance silicon, the relative dielectric constant is 11.69, the resistivity is 5k omega cm, and the thicknesses are both 80-120 mu m. The terahertz incident channel 5 and the terahertz emergent channel 6 are both rectangular, the width is 570-590 um, and the length is 4-5 mm; the sample bearing area 7 is rectangular, the length L is 6-8 mm, and the width w is 3-6 mm. In addition, the width w of the first biconical long straight waveguide 4 0 Can be selected to be 170-190 um, and the thickness is 80-120 um. The bending radius R of the second curved waveguide 8 can be selected to be 0.9-1.1 mm, and the width w 0 170-190 um can be selected, and the thickness is 80-120 um. The remaining component dimensional parameters do not directly affect the performance of the device and therefore may be adjusted without limitation, depending on the implementation.
Therefore, the novel waveguide with the silicon-benzocyclobutene-quartz structure is used in the terahertz wave absorption spectrum, the absorption characteristics of the material are captured based on the interaction between the evanescent field and the sample material around the waveguide, and the terahertz wave absorption spectrum intensity is enhanced.
The device can be used for realizing enhanced terahertz absorption spectrum measurement of biological samples (including solution samples), and taking polycrystal alpha-lactose as an example, the device shown in fig. 1 or fig. 2 is used for carrying out the polycrystal alpha-lactose terahertz absorption spectrum measurement method, which specifically comprises the following steps: firstly, adding polycrystalline alpha-lactose to be detected into a sample bearing area 7, and fully contacting with the biconical long waveguide; then, terahertz waves are focused by a lens and input into the biconical long waveguide through the input end of the biconical long waveguide, corresponding evanescent waves are formed on the surface of the waveguide, an electromagnetic enhancement effect is generated near the waveguide so as to enhance the interaction between the incident terahertz waves and the alpha-lactose material in the sample bearing area 7, the absorption of the alpha-lactose material on the incident waves is enhanced near the surface plasmon resonance frequency point, and the terahertz reflected signals after the interaction are emitted from the output end of the biconical long waveguide and then detected.
The following is a description of specific technical effects based on the above two device forms by way of example respectively.
Example 1
In the embodiment, a silicon-benzocyclobutene-quartz device structure capable of obtaining a broadband enhanced terahertz absorption spectrum is provided. As shown in fig. 1, the terahertz waveguide comprises a quartz substrate 1, a benzocyclobutene dielectric layer 2, a silicon waveguide 3, a biconical long straight waveguide 4, a terahertz incident channel 5, a terahertz emergent channel 6 and a sample bearing region 7, and the specific structure is as described above and is not described again. The material parameters of the components were as follows:
the quartz substrate 1 is made of quartz and has a relative dielectric constant of 4.45; the benzocyclobutene dielectric layer 2 is made of benzocyclobutene, has a relative dielectric constant of 2.45 and a loss tangent at 1THz of only 7-9 multiplied by 10 -3 . The silicon waveguide 3 and the biconical long waveguide are made of high-resistance silicon, the relative dielectric constant is 11.69, the resistivity is 5k omega cm, and the thickness is 100 mu m. The terahertz incident channel 5 and the terahertz emergent channel 6 are both rectangular, the width is 580um, and the length is 5 mm; the sample bearing area 7 is rectangular, the length is 8mm, the width is 5mm, the length of the biconical long straight waveguide 4 isThe width is 180um, and the thickness is 100 um.
Polycrystal alpha-lactose of a sample to be detected is filled in a sample bearing area to carry out terahertz absorption spectrum measurement, and the lactose is important disaccharide and is used in the fields of food and medicines. Alpha-lactose (one of the isomers of lactose) has an absorption characteristic peak around a frequency of 532GHz, and this example was tested using 20mg of polycrystalline alpha-lactose sample material, although in practice the amount of sample material used can be reduced by reducing the width w of the sample-bearing zone 7. During measurement, broadband terahertz waves are focused by a lens and then are injected into a long-wave guide 4 in a terahertz injection channel 5, when the injected terahertz waves pass through the biconical long straight waveguide 4, corresponding evanescent waves are formed on the surface of the waveguide, an electromagnetic enhancement effect is generated near the waveguide, the interaction between the injected terahertz waves and an alpha-lactose material in a sample bearing area 7 can be enhanced, the absorption of the injected waves by the material is enhanced near a surface plasmon resonance frequency point, and terahertz reflection signals after the interaction are injected from a terahertz wave injection channel 6 through the output end of the biconical long straight waveguide 4 and then detected. When the sample-bearing zone 7 is filled with an alpha-lactose material, the transmission signal through the waveguide will generate a falling peak around 532GHz, resulting in an absorption peak (long straight waveguide curve) as shown in fig. 3.
Example 2
The main purpose of the present embodiment is to verify that the interaction between the terahertz wave and the sample material can also be enhanced by increasing the length of the interaction. In this embodiment, as shown in fig. 2, the biconical long straight waveguide 4 of the device structure in fig. 1 is replaced by a curved waveguide 8, where the curved waveguide has a bending radius R of 1mm, and the width and thickness of the curved waveguide are consistent with those of the biconical long straight waveguide 4. The remaining structure of the device and the materials and parameters of the components were the same as in example 1. Broadband terahertz waves are focused by a lens and then are injected into a bent waveguide 8 in a terahertz injection channel 5, when the injected terahertz waves pass through the bent waveguide 8, corresponding evanescent waves are formed on the surface of the waveguide, an electromagnetic enhancement effect is generated near the waveguide, the interaction between the injected terahertz waves and an alpha-lactose material in a sample bearing area 7 can be enhanced, and the absorption of the material on the injected waves is enhanced near a surface plasmon resonance frequency point. Compared with the biconical long straight waveguide 4, the bent waveguide 8 can effectively increase the length of the interaction between the terahertz evanescent wave and the sample material on the premise of not increasing the structure size, and can further enhance the terahertz absorption spectrum. The acted terahertz reflection signal is emitted from the terahertz wave emission channel 6 through the curved waveguide 8 to be detected. When the sample-bearing zone 7 is filled with an alpha-lactose material, the transmission signal through the waveguide will generate a falling peak around 532GHz, resulting in an absorption peak (curved waveguide curve) as shown in fig. 3.
As can be seen from fig. 3, there is a significant difference in the terahertz spectrum absorption curves when two different waveguide structures in example 1 and example 2 are used. The peak value of the absorption of the terahertz absorption spectrum corresponding to the curved waveguide structure is obviously stronger (by 5.6 times) than the peak value measured by using a long straight waveguide, which is mainly caused by the longer interaction length in the curved waveguide.
The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical solutions obtained by means of equivalent substitution or equivalent transformation all fall within the protection scope of the present invention.
Claims (10)
1. The device is characterized by being formed by stacking different functional layers, namely a silicon waveguide (3), a benzocyclobutene dielectric layer (2) and a quartz substrate (1) from top to bottom in sequence, wherein the silicon waveguide (3) is provided with a terahertz incident channel (5), a terahertz emergent channel (6) and a sample bearing region (7), and the terahertz incident channel, the terahertz emergent channel and the sample bearing region penetrate through the surface of the benzocyclobutene dielectric layer (2); the sample bearing area (7) is positioned in the center of the silicon waveguide (3) and used for bearing a sample to be tested, and the terahertz incident channel (5) and the terahertz emergent channel (6) are respectively connected to two sides of the sample bearing area (7); the double-conical long waveguide is paved on the surface of the benzocyclobutene dielectric layer (2) along the terahertz incident channel (5), the sample bearing area (7) and the terahertz emergent channel (6), one end of the double-conical long waveguide, which is positioned at the terahertz incident channel (5), serves as an input end, and one end of the double-conical long waveguide, which is positioned at the terahertz emergent channel (6), serves as an output end; terahertz waves are input from the input end, evanescent waves can be generated on the surface of the waveguide, interaction between the terahertz waves in the sample bearing area (7) and a sample to be detected is enhanced, and terahertz wave signals after the interaction are output from the output end.
2. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film according to claim 1, wherein the biconical long waveguide is a biconical long straight waveguide (4) and is laid along a terahertz incident channel (5), a sample bearing region (7) and a terahertz emergent channel (6) in a straight line.
3. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement chip as claimed in claim 1, wherein the biconical long waveguide is a curved waveguide (8), and the waveguide section located in the sample carrying region (7) is curved in a wavy line.
4. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film as claimed in any one of claims 1 to 3, wherein the material of the quartz substrate (1) is quartz, and the relative dielectric constant is 4.45.
5. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film as claimed in any one of claims 1 to 3, wherein the material of the benzocyclobutene dielectric layer (2) is benzocyclobutene, and the relative dielectric constant is 2.45.
6. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film according to any one of claims 1 to 3, wherein the waveguide material of the silicon waveguide (3) and the biconical long waveguide is high-resistance silicon, the relative dielectric constant is 11.69, the resistivity is 5k Ω -cm, and the thickness is 80 to 120 μm.
7. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film as claimed in any one of claims 1 to 3, wherein the terahertz incident channel (5) and the terahertz emergent channel (6) are both rectangular, have a width of 570-590 um and a length of 4-5 mm; the sample bearing area (7) is rectangular, the length is 6-8 mm, and the width is 3-6 mm.
8. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film as claimed in any one of claims 1 to 3, wherein the biconical long straight waveguide (4) has a width of 170 to 190 μm and a thickness of 80 to 120 μm.
9. The device for terahertz vibration absorption spectroscopy on a silicon waveguide enhancement film as claimed in any one of claims 1 to 3, wherein the bending radius of the curved waveguide (8) is 0.9 to 1.1 mm.
10. A terahertz absorption spectroscopy measurement method of polycrystalline alpha-lactose by using the device as claimed in any one of claims 1 to 9, wherein firstly, polycrystalline alpha-lactose to be measured is added into a sample bearing area (7) and is fully contacted with the biconical long waveguide; then, terahertz waves are focused by a lens and input into the biconical long waveguide through the input end of the biconical long waveguide, corresponding evanescent waves are formed on the surface of the waveguide, an electromagnetic enhancement effect is generated near the waveguide so as to enhance the interaction between the incident terahertz waves and the alpha-lactose material in the sample bearing area (7), the absorption of the alpha-lactose material on the incident waves is enhanced near the surface plasmon resonance frequency point, and the terahertz reflection signals after the interaction are emitted from the output end of the biconical long waveguide and then detected.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008241340A (en) * | 2007-03-26 | 2008-10-09 | Institute Of Physical & Chemical Research | Terahertz wave spectral measuring instrument and method |
| CN105445219A (en) * | 2016-01-07 | 2016-03-30 | 上海理工大学 | Method for enhancing absorption spectrum signals of biological sample in Terahertz wave band |
| CN114527090A (en) * | 2022-02-23 | 2022-05-24 | 中北大学 | Terahertz biosensor based on combination of coplanar waveguide and resonant structure |
| CN217641734U (en) * | 2022-07-01 | 2022-10-21 | 浙江中环检测科技股份有限公司 | Terahertz vibration absorption spectrum device on silicon waveguide enhancement chip |
-
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- 2022-07-01 CN CN202210775310.5A patent/CN115036665A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008241340A (en) * | 2007-03-26 | 2008-10-09 | Institute Of Physical & Chemical Research | Terahertz wave spectral measuring instrument and method |
| CN105445219A (en) * | 2016-01-07 | 2016-03-30 | 上海理工大学 | Method for enhancing absorption spectrum signals of biological sample in Terahertz wave band |
| CN114527090A (en) * | 2022-02-23 | 2022-05-24 | 中北大学 | Terahertz biosensor based on combination of coplanar waveguide and resonant structure |
| CN217641734U (en) * | 2022-07-01 | 2022-10-21 | 浙江中环检测科技股份有限公司 | Terahertz vibration absorption spectrum device on silicon waveguide enhancement chip |
Non-Patent Citations (1)
| Title |
|---|
| HADI AMARLOO 等: "Enhanced on-chip terahertz vibrational absorption spectroscopy using evanescent fields in silicon waveguide structures", OPTICS EXPRESS, vol. 29, no. 11, 24 May 2021 (2021-05-24), pages 17343 - 17352 * |
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